I. Field of the Present Invention
The present invention relates generally to apparatus for automaticaly installing caps on necked containers, and more particularly to apparatus for installing particularly configured caps adapted to snap-lock with the neck of the container.
II. Description of the Prior Art
It has been previously been known to automate the installation of caps on necked containers for simple cap structures. For example, an internally threaded cap can be applied to an externally threaded neck by holding the cap in the chuck or the like and then rotating the chuck as it descends in registration with the container neck. Typically, the containers are moved along the conveyor line, and the chuck must therefore be linearly displaced at the same speed as the container while the cap remains in the chuck and in engagement with the container neck. While such devices are advantageous for use in packaging containers of the simple cap structure, the previously known apparatus are not well adapted for use in installing specially configured caps.
A particularly advantageous form of cap which has become available includes a pour spout for controlling the flow of contents from the container as the container is tilted. One particular type of pour spout cap includes a raised spout extending upwardly beyond a rim and supported by an inclined base disposed below the rim. The base has an opening at its lowermost end communicating with an elongated slot in the pour spout. The rim includes a depending lip having means for engaging a peripheral projection on the neck of the container so that the cap can be snap-locked in position on the neck. The inner peripheral wall of the rim is threaded to receive a closure cap which completely covers the open spout, and thus the open neck of the container. When the closure cap is removed, the closure cap is designed to measure a predetermined amount of the contents of the container being poured into the closure cap through the spout. A particular advantage of such packaging enclosures is that any residue contained within the closure cap is returned to the container when the closure cap is remounted to the rim of the pour cap since the residue drains along the inclined base of the pour cap into the container. Since the pour cap has a spout extending upwardly above the rim, and a base inclined downwardly from the rim, the previously known capping apparatus are not well adapted for installing such caps.
Moreover, when the peripheral projection on the neck of the container is continuous around the entire neck, a substantial amount of force would be necessary to concentrically depress the cap upon the neck of the container. Moreover, displacement of the means for depressing the cap along a moving conveyor line must be timed accurately to correspond with the movement of the container along the line. The application of a depressive force when the cap is misaligned with respect to the neck, or application of an excessive force, can cause damage to the cap or the container neck and prevent tight sealing engagement between the cap and the container.